Black, gray & white bracelet of rock crystal and black Onyx.

Onyx is a mineral and a variety of quartz, more specifically a variant of chalcedony. Onyxes are two-tone nesosilicates, where the colors are intertwined as layers or bands. Onyx is related to agate, a four-colored quartz variant. There are different types of onyxes, with the basic name onyx usually being used to denote a mineral with white and black layers. In addition, we also know the sardonyx with white and red-brown (the color called sard) layers and carnelian or carnelian onyx (fire red and white layers). Onyx is found in Brazil, Madagascar, Mexico, Uruguay, the United States and Pakistan. In ancient times, carnelian was mined in North Africa as an ornamental stone. In the Imperial era, onyxes were mainly used for the manufacture of gemstones; rings with such stones were regularly found in the western provinces. In late Roman times we also find carnelian pearls in the eastern provinces. Above the Alps, carnelians only occurred occasionally, such as in Pfyn and Switzerland. References to the onyx appear in several places in the Old Testament of the Bible, the first being in Genesis 2, verse 12. According to Rabbi Bahya ben Asher, the word "shoham" in Exodus 28:20 means onyx. According to him, onyx was also the stone on the ephod that stood for the tribe of Joseph. In addition, the shoulders of the ephod were also provided with two such "shoham" stones. The onyx has an esoteric history almost as long as its secular history. In the Middle Ages, the onyx was already seen as a "doom stone", a symbol of mourning and misery. Other sources say it was also a healing stone, with a positive effect on the skin, hair and nails. Within the zodiac, onyx is associated with Capricorn and Saturn. Onyx is also said to have a beneficial effect against nausea, hypersensitivity to the weather and stomach and intestinal complaints.